1. Field of the Invention
The present invention relates to an electrical socket assembly, and more particularly to an electrical socket assembly that conforms to universal serial bus (USB) specifications, and that has the ability to transmit both USB- and non-USB-compliant signals. The present invention relates also to a plug connector that is electrically coupled to the electrical socket assembly for transmitting the non-USB-compliant signals.
2. Description of the Related Art
It is becoming the standard for digital devices that interface with a PC (personal computer) to be USB-based. Examples of such digital devices include MPEG (Moving Pictures Experts Group) Audio Layer-3 players, which are commonly referred to simply as MP3 players, digital cameras, and digital camcorders.
In the case of the MP3 player, this digital device typically includes the player itself with all the required circuitry and buttons for user manipulation, an audio port, and a data port. An MP3 player is used in conjunction with a pair of earphones or headphones, and a cable for connection to a PC. An earphone connector of the earphones is connected to the audio port of the MP3 player. The cable, assuming that the MP3 player is USB-based, has a USB “A” connector on one end for connection to a USB socket of a PC, and a mini USB “B” connector on its other end for connection to the data port of the MP3 player. There are many different types of mini USB “B” connectors, but the USB “A” connector is standardized to enable coupling to the USB socket of any PC or USB hub.
In order to listen to music, the user connects the earphones to the audio port, and operates the MP3 player. When desiring to transfer MP3 files from the PC to the MP3 player, the user connects the mini USB “B” connector of the cable to the data port of the MP3 player, and the USB “A” connector of the cable to the USB socket of the PC. Hence, two different ports are required for one MP3 player. This runs counter to efforts at making the MP3 player more lightweight and compact, and increases overall manufacturing costs. Another drawback of the conventional configuration is that the connection life between the earphone connector of the earphones and the audio port of the MP3 player is limited, i.e., approximately 10,000 connections. That is, wear in at least one of the elements becomes too severe following 10,000 connections and disconnections. This is in contrast to USB connectors and sockets, which have a connection life of approximately three times that of other connectors and sockets, such as the earphone connector and audio port.